Sounds like you could be bisexual although it doesn't sound like a strong urge because it doesn't seem as if you put yourself in a place to experiement with being with men.

You threw transgender in the mix but you haven't mentioned not feeling like you have the correct body parts - which is usually the feeling with those who are transgender. If you are happy with being a man then I do not think that you are transgender.

If you are depressed or on any kind of anxiety drugs, etc., you may be just experiencing a low sex drive due to the drugs.